1. Field of the Invention
This invention relates to job site, factory fabricated and modular structural systems for facilitating the rapid construction of roofs, floors, and foundations in family dwellings, including mobile homes, and commercial structures, and more particulary, to new and improved composite framing assemblies having exceptionally good insulating, sound deadening, and shock resistant properties in addition to high strength, in such structures. The invention enhances the shock resistant and load-carrying capability of conventional structures and also provides good insulating and sound deadening properties for such improvements.
2. Description of the Prior Art
Heretofore, the principal method of building homes, including mobile homes and commercial buildings has been digging footings, pouring concrete and installing piers, in the case of mobile homes, or digging footings, setting forms and pouring a concrete slab, all at substantial cost. Such variables as weather conditions, the availability of labor, and the time required to complete the job combine to make such conventional operations expensive and time-consuming. For example, after the slab is poured, conventional wall framing and floor framing must be undertaken, which again requires coordination between labor and materials, and necessarily results in dependence upon good weather.
After the floor and wall framing operations have been completed, the roof must be built, and coordination of labor and materials and good weather are factors which frequently necessitate additional expense and time in construction. With the ever increasing cost of labor and materials, any construction procedure which can be utilized to cut down the time of construction and to make best and most efficient use of materials necessarily results in decreased construction costs.
It has been found that use of expanded foam materials such as expanded polyurethane foam can be very useful as a material of construction. For example, expanded polyurethane retains structural integrity under both compressive and tensile loading conditions and is characterized by excellent insulating properties. Rigid urethane foam having a density of about two pounds per cubic foot has been found to withstand compressive loads of up to about 35 pounds per square inch with only a ten percent deflection. Foam of the same density will also withstand a tensile load of up to about 35 pounds per square inch. When the foam density is increased to five pounds per cubic foot the compressive load necessary to realize a 10 percent deformation rises to slightly in excess of 100 pounds per square inch, and the tensile load increases to about 120 pounds per square inch.
Accordingly, it is an object of this invention to provide a composite framing assembly which utilizes an expanded foam material having a density of from about two to about six pounds per cubic foot.
Another object of the invention is to provide a composite framing assembly which utilizes foundation, floor and roof sections.
Yet another object of the invention is to provide a foundation, floor, and roof composite framing assembly for substantially any structure, wherein extensive excavation of the site, digging and pouring of concrete footings and the setting of forms or the driving of piles is not necessary to provide a firm foundation.
Another object of the invention is to provide a composite framing assembly which requires less time to implement than conventional systems, thereby saving money in construction costs.
A still further object of the invention is to provide composite foundation, floor and roof framing assemblies which have superior load bearing, sound deadening, shock resistant and insulation characteristics, and in which the floor assembly may also serve as a foundation assembly as well as a multiple floor assembly.
Yet another object of the invention is to provide a composite framing assembly for constructing foundations, floor systems and roof systems, respectively for structures, which assembly may be prefabricated or assembled as a modular unit or, in the alternative, may be formed and reenforced as described herein and foamed in place as a single unit with walls constructed in accordance with known techniques, and has superior insulating, sound deadening, shock resistant and load bearing characteristics.
Another object of the invention is to provide roof and floor assemblies in which the bottom component in the assemblies serves to form the ceiling of the structure.